Refrigerating apparatus



1949 E. w. ZEARFOSS, JR 2,492,611

REFRIGERAT ING APPARATUS Filed Nov. 30, 1944 2 Sheets-Sheet l .Zizuenr,'

1949 E. w. ZEARFOSS, JR 2,492,611

REFRIGERATING APPARATUS 2 Sheets-Sheet 2 Filed Nov. 30, 1944 zwe'nfzrPatented be. 21, 1949 REFRIGERATING APPARATUS Elmer W. Zearfoss, Jr.,Philadelphia, Pa., assignor, by mesne assignments, to lhilcoCorporation, Philadelphia, Pa., a corporation of PennsylvaniaApplication November so, 1944, Serial No. 565,843

11 Claims. (Cl. ez-us) The present invention relates to refrigeratingapparatus and particularly to motor-compressors for refrigeratingsystems. More specifically, the invention pertains to improved means forcooling motor-compressorunits .of the hermetically sealed type. r

It is an object of the invention to provide means whereby amotor-compressor unit of the general type above referred to may beeffectively cooled by forcibly spraying over the unit a cooling medium,such as oil, from a permanent supply,

-,without necessitating material change in the basic structure of saidunit, which arrangement employs the normal function of the compressorpiston to create a pressure within an oil reservoir inside themotor-compressor housing for displacing the oil from said reservoir foruse thereof in cooling the unit.

Other objects and advantages of the invention will appear in thefollowing description which is based upon the accompanying drawings,

' wherein:

Fig. l is a transverse vertical sectional view of a hermeticmotor-compressor unit in association with a refrigerating system andillustrating one embodiment of the invention;

Fig. 2 is a view similar to Fig. l but illustrating another form of theinvention; and

Figs. 3 and 4 are cross-sectional detail views on an enlarged scale ofcertain port and valve members included in that form of the inventionshown in Fig. 2.

In Fig. 1 of the drawings, the invention is shown as applied to theimproved multi-stage refrigerantcompressing system described and claimedin my copending application, Serial No. 565,842, filed November 30,1944; whereas in Fig. 2 of the drawings, the invention is shown asapplied said multi-stage refrigerant compressing system is incorporatedin a refrigerant circulating circuit which, conventionally, includes anevaporator l and a condenser 2, a suitable refrigerant fiow restrictor 3being interposed between said evaporator and condenser. The compressingsystem basically comprises a compression chamber 0, a hermeticallysealed space Sand pressure responsive means M, the latter being adaptedto control the initiation of the first and second stage operations ofsaid system.

As shown, the chamber C is defined by a cylinder 4 in which a piston 5is mounted for reciprocatory motion under operation by a suitable motor8. and the space S is defined by a housing I which hermetically sealsthe motor-compressor unit. As also shown, the pressure responsive meansM is in the form of a multiple valve mechanism comprising a valve body 8and a pair of spaced, interconnected valve members, 9 and [0respectively, each adapted to cooperate with valve seats i3 and Ill.

to the conventional single-stage refrigerant coma.

pressing system.

It is pointed out that when the valve members 9 and it are seated ontheir respective seats it, that is, in the position shown in full lines,the system will function for first stage operation. In this position ofthe valve members, a port 2|, which is connected with a conduit 22leading from the refrigerant evaporator 2|, communicates with a port 23connected with a conduit 24 leading to the compression chamber C; and aport 25 connected with a conduit 26 leading from said chamber 0,communicates with a port 21 which is connected with a conduit 28 leadingto the hermetically sealed space S. When the valve members 9 and III areseated on their respective seats It, that is, in the position shown indotted lines, the system will function for second-stage operation. Inthis position of the valve members, the port 23 communicates with port21, and port 25 with a port 29 connected with a conduit 30 leading tothe refrigerant condenser 2.

In practice, an interstage pressure varying between a predeterminedminimum value of, say, 50 pounds per square inch absolute and apredetermined maximum value of, say, pounds per square inch absoluteis'maintained within the space S, and in operation, if the interstagepressure within the space S is reduced to its minimum value, then thevalve members 9 and it move to first-stage position, that is, to theposition shown in full lines. The flow of refrigerant is .then asindicated by the solid arrows in Fig. 1, that is, gaseous refrigerant atsuction pressure of, say, 15 pounds per square inch absolute orsubstantially atmospheric pressure, is admitted to'the compressionchamber C through conduit 22, port 2|, port 23 and conduit 24, and isdischarged at an elevated pressure into the hermetically sealed space Sthrough conduit 26, port 25, port 21 and conduit 28. Continued pumpingof the refrigerant causes the pressure in said space to graduallyincrease until the interstage pressure reaches its predetermined maximumvalue, say, 55 pounds per square inch absolute, which causes valvemembers 9 and Hi to move to second stage position, that is, the positionshown in dotted lines. The flow of refrigerant is then as indicated bythe broken arrows in Fig. 1, that is, gaseous refrigerant at interstagepressure passes into the compression chamber C through conduit 28, port21, port 23 and conduit 24, and is discharged at higher pressure, say,180 pounds per square inch abso lute, into the condenser through conduit28, port 25, port 29 and conduit 30. The high pressure gaseousrefrigerant gives up its heat in the condenser 2 and condenses thereinto return, as liquid, to the evaporator. This second stage operationcontinues until the interstage pressure within the space S is reduced toits predetermined minimum value, whereupon valve members 9 ad l returnautomatically to their initial positions thereby initiating anotherfirst stage operation.

A blow-off port 35 in the side wall of the compressor cylinder 4 and anassociated valve 38 are provided for bleeding off apart of the gaseousrefrigerant during second stage operation of the system so that theweight of refrigerant handled during both the first and second stagesmay be substantially balanced and, therefore, the work performed perstroke, and the number of strokes required for each stage, therebyequalized.

An inter-cooler 40 of known structure may be included in the system toremove the heat of first stage compression; and the system may includean overload cutoff arrangement generally indicated at 4| which functionsto prevent the imposition of excessive load on the motor, particularlyduring pull down periods, that is, during those periods when theevaporator I is working at abnormally high temperatures, such as is thecase, for instance, during defrosting cycles.

The system, in so far as described, is the same as that disclosed in myco-pending application aforesaid, and for a more detailed description ofthe construction and operation of such a system, reference may be had tosaid co-pending application.

In accordance with the present invention, the aforesaid bleeding of apart of the relatively heavy gaseous refrigerant is utilized for pumpingand spraying a cooling medium, such as oil, internally of themotor-compressor housing I to cool the motor-compressor unit.

For that purpose, the housing I is provided with a partition 50 spacedfrom the bottom of said housing to define a reservoir 52 in the latter.The partition 50 is shaped to cooperate with the adjoining portions ofthe housing I to form a sump 53 adapted to retain a supply of oil as iscustomary in motor-compressor units of the general type shown. Thepartition 50, moreover, has an aperture 54 therein, said apertureestablishing communication between the sump 53 and reservoir 52 so thatoil may pass from said sump to the reservoir. Suitable valve means, suchas disc type valve 55, is associated with the aperture 54 to control thecommunication between the sump 53 and the reservoir.

A length of tubing 55 extends from the blowoff casing 35 into thereservoir 52 and an oil riser tube 51 extends from said reservoir to apoint above the motor 5 in close proximity to the inside surface of thetop wall 58 of the motorcompressor housing I. An equalizer tube 59, having one end 60 opening into the reservoir 52 and the other end 6|extended into the space S to a point above the oil level therein, ispreferably provided to establish communication between said space andreservoir when the check valve 55 is opened, it being noted that the end60 of the equalizer tube 59 is arranged to be sealed oil by said valvewhen the latter is closed.

In the operation of the system, when, during first stage compression,gaseous refrigerant at suction pressure, say, 15 pounds per square inchabsolute, is drawn into the compression chamber C, the valve 35 remainsclosed because then the pressure in said chamber is lower than thepressure in the casing 35. However, during first stage compression,compressed gaseous refrigerant is discharged into the space S toincrease the pressure therein so that the force of the increasingpressure in said space plus the force of gravity unseats the check valve55, thus-allowing oil to flow into the reservoir 52. The gas beingdisplaced by the oil entering said reservoir, escapes to the space Sthrough the equalizer tube 59.

Since during second stage compression gaseous refrigerant, at interstagepressure, is passing from the space S to the compression chamber C, thepressure in said chamber tends to decrease, but since a part of suchgaseous refrigerant is being bled through the blow-off port 35 and valve38 into the casing 36 and thence through tube 55 into the reservoir 52,the pressure in the latter tends to increase.

The increased pressure in the reservoir 52 causes the disc valve 55 toclose, thereby unbalancing the pressures in the space S and reservoir52. This unbalancing of pressures forces the oil up through the risertube 51 and forcibly discharges the oil against the inner surface of themotor-compressor housing I, causing the oil, cooled by contact with thewall of the housing, to drip downwardly and to cool the unit.

A check valve 62, preferably in'the form of a ball 63, associated withthe discharge end of the riser tube 51, serves as a means to preventdownward flow through said tube and also as a nozzle to effect sprayingof the oil when forcibly emitted through said discharge end.

It will be appreciated that by properly proportioning the elementsthrough the medium of which oil pumping is attained, a considerablequantity of oil may be circulated during each second stage compression,or in other words, during approximately 50% of the time.

If desired, the riser tube 51 may be circulated externally of themotor-compressor housing as indicated at 64, thereby enhancing thecooling effect.

Fig. 2 shows an ordinary refrigerating system comprising an evaporatorla, a condenser 2a, a fiow restrictor 3a, and a motor-compressor unit.The motor-compressor unit shown is of the well known hermetic typeincluding a compression chamber C, which takes the form of a cylinder laprovided with a piston 5a actuated by a motor 5a, said unit being sealedin a housing 1a.

The construction and operation of systems of thi type are known in theart. The evaporated shown in Fig. 2, a blow-off port 35a, opening to acasing 36a, is provided in the side wall of the compressor cylinder 4a,and a valve 38a is associated with said port to allow a part of thegaseous. refrigerant being compressed in the chamber C to escapetherefrom. The location of the port 35a is such that blow-off occursonly during a small percentage of the total compression stroke of thepiston a. Also, in this form of the invention a partition 50a and aseparator member 50b are provided in the lower portion of the housing laand are disposed in relation to the bottom 51a of said housing to definea pair of reservoirs 52a and 52b. The partition 50a is shaped tocooperatewith the adioining portions of the housing to form a sump 53aadapted to retain a supply of oil. The partition, moreover, has a pairof apertures 54a and 541), which respectively establish communicationbetween the sump 53a and the reservoir 52a, and between said sump andthe other reservoir 52b. Suitable valve means,

such as disc type valve, 55a and 55b are respectively associated withthe apertures 54a and 54b to control communication between the sump andthe respective reservoirs 52a and 52b. For that purpose and as moreclearly shown in Fig. 3, the apertures 54a and 541) may be provided withseat-forming elements 64 for the disc valves 55a and 55b, and the valvesmay becsupported by means of retainer rings 65 having spaced raisedportions 66 to permit the flow of oil from the sump 53a into therespective reservoirs 52a and 52b.

Lengths of tubings 56a and 56b extend from the blow-oil casing 36a intothe reservoirs 52a and 52b respectively. As more clearly shown in Fig.4, the ends of the tubings 56a and 5% are preferably connected with theblow-off casing 36a by means of bushings 61a and 611), each of which andin each of the reservoirs lie and 52b is equalized because of thecommunication between said reservoirs and space. Under these conditionsthe disc valves 55a and 55b uncover the apertures 54a and 54b allowingoil to fill the reservoirs 52a and 521).

At the initiation of an on cycle, assuming that the ball valve 69 coversthe tubing 56b, then compressed gaseous refrigerant will escape throughthe tubing 56a into the reservoir 52b, thus keeping the latter at apressure above the suction pressure of the system, such suction pressurebeing the pressure against which oil must be pumped. In other words, thegaseous refrigerant escaping into the casing 36a tends to expand andflow through the tubing 56a into the reservoir has a valve seat, 68a and68b respectively, disposed in angular relationship so that a singlevalve element, such as a ball 69, may seat itself upon either valve seat68a or 681), as illustrated in Fig. 6. Referring again to Fig.v 2, ariser tube 51a having one end disposed for communication with thereservoirs 52a or 52b, extends to a point above the motor 60. in closeproximity to the inside surface of the top wall 58a of the motor .0

retainer rings 12a and 12b may be mounted in said cross bore to provideseats for oppositely facing spring urged valvev elements 131; and 13b.The operation of the system shown in Fig. 2, is as follows:

During off cycles, that is, when the motorcompressor is idle, thepressure in the space S 52a, thus increasing the pressure tending toforce the oil up the riser tube 51a and against the inner surface of themotor-compressor housing.

During this pumping action, the valve disc "a is held in closed positionsealing the aperture 54a due to the pressure force in the reservoir 52a.Since the gaseous refrigerant emitted in the reservoir 52a must displacethe oil by forcing it through the riser tube 51a, the flow rate isrestricted until the 'oil level in said reservoir 52a falls below thevalve controlled opening to the riser tube. The gas flow then isvirtually unimpeded as it passes up the riser tube. This increased gasflow or increased velocity of gas passing the ball 69 exerts a force onsaid ball in a direction to move the same from its posi-,

the oil above said valve, so that oil then flows into the said reservoir52a. The gaseous refrigerant displaced by the oil as it accumulatesinthe reservoir, escapes through the aperture 540., Y

or through an equalizer tube similar to the tube 59 in Fig. 1, whichtube may be included, if de-- sired, in the structure shown in Fig. 2.

-When theoil pumping cycle on reservoir" 52? is completed, the gasvelocities acting on the ball 69 are again increased and operate in themanner hereinbefore described to return said ball into a position'toclose tube 56b and open tube 56a.

From the foregoing, it will be apparent that the force effects of gasvelocity on ball '69 will in- I crease and move the ball when an oilpumping cycle is completed in either reservoir 52a or 521).

In the meantime, the other reservoir has been filling so that it isready to deliver oil upon conclusion of an oil pumping cycle in thefirst reser-' voir. 1

It will be apprecited that by utilizing the sys-" tem of the presentinvention it is possible to obtain cooling of a motor-compressor unit byspraying a cooling medium, such as oil, internally of themotor-compressor housing, the spraying being accomplished by thefunction of the compressor itself so that no additional pumpingmechanism-' is required for the purpose.

It is to be understood that the invention is not limited to theparticular structural embodiments herein shown and described, and thatsuch em- I bodiments may be modified within the scope of" the appendedclaims.

I claim:

1. In a. refrigerating apparatus, a. housing, a

compressor unit enclosed in said housing and including a compressionchamber for increasing the pressure of expanded refrigerant, an oilreservoir, means in communication with said chamber and reservoir fordiverting a part of the compressed refrigerant under pressure to thereservoir for displacing oil from said reservoir into contact first withwall-portions of said housing to cool such oil and then with said unitto cool the latter, a condenser, and means in communication with saidchamber and condenser for discharging another part of the compressedrefrigerant under pressure into the condenser.

2. In a refrigerating apparatus, a housing, a compressor unit enclosedin said housing and including a compression chamber for increasing thepressure of expanded refrigerant, an oil sump in the lower section ofthe housing, a reservoir arranged to receive oil from said sump, andmeans in communication with said chamber for diverting part of thecompressed refrigerant under pressure for displacing oil from saidreservoir into contact first with wall-portions in the upper section ofthe housing to cool such oil and then with the said unit to cool thelatter.

3. In a refrigerating apparatus, a housing, a compressor unit enclosedin said housing and including a compression chamber for increasing thepressure of expanded refrigerant, an oil sump in the lower section ofthe housing, means providing a reservoir arranged to receive oil fromsaid sump, a valve controlled duct between the chamber and reservoir fordiversion of a part of the compressed refrigerant under pressure fromsaid chamber to the said reservoir for displacing oil from the latter,and a duct leading from said reservoir for discharging the displaced oilinto contact first with wall-portions of said housing to cool such oiland then with said unit to cool the latter.

4. In a refrigerating apparatus, a motr-com-' pressor including acompression chamber for increasing the pressure of expanded refrigerant,a housing enclosing the motor-compressor, partition means in one portionof said housing providing an oil sump and a reservoir adapted to receiveoil from said sump, valve controlled port means between said chamber andreservoir for diversion of a part of the compressed refrigerant underpressure from the chamber to the reservoir for displacing oil from thelatter, and means extending from said reservoir to another part of thehousing for discharging the displaced oil interiorly of the latter intocontact first with wall-portions thereof to cool such oil and then withthe motor-compressor to cool the same.

5. In a refrigerating apparatus comprising an evaporator and acondenser, a motor-compressor, a housing enclosing the motor-compressorand adapted to receive expanded refrigerant at suction pressure fromsaid evaporator, said motorcompressor having a compression chamber forincreasing the pressure of the expanded refrigerant and for dischargingthe compressed refrigerant to said condenser, partition means in thelower portion of said housing providing an oil sump and a reservoiradapted to receive oil from said sump, valve controlled port meanscommunicating with the reservoir for admitting compressed refrigerant ata pressure above suction pressure into said reservoir to displace oilfrom the latter, and means leading from said reservoir to a point in theupper portion of the housing for discharging the displaced oilinteriorly of said housing into contact first with wall portions thereofto cool such oil and then with the motorcompressor to cool the same.

6. In a refrigerating apparatus, a housing, a compressor unit enclosedin said housing and including a compression chamber for increasing thepressure of expanded refrigerant, an oil supply, a pair of reservoirsadapted to receive oil from said supply, and means in communication withsaid chamber and operable to direct a part of the compressed refrigerantunder pressure to said reservoirs in alternation for displacing oilsuccessively from the reservoirs into contact first with wall-portionsof the housing for cooling such oil and then with said unit for coolinthe latter.

7. In a refrigerating apparatus, a housing, a compressor unit enclosedin said housing and including a compression chamber for increasing thepressure of expanded refrigerant, an oil supply, a pair of reservoirsadapted to receive oil from said supply, means in communication withsaid chamber and operable to direct a part of the compressed refrigerantunder pressure to said reservoirs in alternation for displacing oil fromthe reservoirs successively into contact first with wall-portions of thehousing to cool such oil and then with said unit to cool the latter, andmeans for refilling each of said reservoirs while oil is being displacedfrom the other reservoir.

8. In a refrigerating apparatus, a motor-compressor including acompression chamber for increasing the pressure of expanded refrigerant,a housing enclosing the motor-compressor, partition means in the lowerportion of said housing providing an oil sump and a pair of reservoirseach adapted to receive oil from said sump, valve controlled port meansconnecting said chamber and reservoirs and operable to divert a part ofthe compressed refrigerant under pressure to said reservoirs fordisplacing oil from the reservoirs alternately, and conduit meansextending from the reservoirs to the upper portion of the housing fordischarging the displaced oil interiorly of the latter into contactfirst with wall-portions thereof to cool such oil and then with themotorcompressor to cool the same.

9. In a refrigerating apparatus, a motor-compressor including acompression chamber for increasing the pressure of expanded refrigerant,a housing enclosing the motor-compressor, partition means in the lowerportion of said housing providing an oil sump and a pair of reservoirseach adapted to receive oil from said sump, valve controlled port meansconnecting said chamber and reservoirs and operable to divert a part ofthe compressed refrigerant under pressure to said reservoirs inalternation for displacing oil from the reservoirs successively, conduitmeans extending from the reservoirs to the upper portion of the housingfor discharging the displaced oil interiorly of the latter into contactfirst with wall portions thereof to cool such oil and then with themotor-compressor to cool the same, and means for refilling each of thereservoirs while oil is being displaced from the other reservoir.

10. In a refrigerating apparatus comprising an evaporator and acondenser, a motor-compressor including a compression chamber, ahermetically sealed housing enclosing the motor-compressor, conduitmeans interconnecting said evaporator, condenser, compression chamberand housing for the circulation of refrigerant therethrough, a deviceinterposed in said conduit means and operable to initiate first andsecond stage compression operations in said chamber, said deviceincluding valve means movable into two alternative positions in responseto pressure variations in said housing, said valve means in one of saidpositions establishing communication between the evaporator andcompression chamber and between said chamber and the housin therebyinitiating first stage compression, and in the other of said positionsestablishing communication between said housing and chamber and betweensaid chamber and condenser, thereby initiating second stage compression,means in the lower portion of said housing providing an oil sump and areservoir adapted to receive oil from said sump during first stagecompression,

means in communication with said chamber operable to bleed a part of therefrigerant out of said chamber and into said reservoir during secondstage operation thereby to displace oil out of the reservoir duringsecond stage compression, and conduit means extending from the reservoirto a point in the upper portion of the housing for discharging thedisplaced oil interiorly of the latter into contact first withwall-portions thereof to cool such oil and for subsequent diversion ofthe oil from said wall into contact with the motor-compressor to coolthe latter.

11. In a refrigerating apparatus having an evaporator and a condenser, amotor-compressor including a compression chamber, a hermetically sealedhousing enclosing the motor-compressor, conduit means interconnectingsaid evaporator, condenser, compression chamber and housing for thecirculation of refrigerant therethrough, a device interposed in saidconduit means and operable to initiate first and second stagecompression operations in said chamber, said device including valvemeans movable selectively into two positions in response to' pressurevariations in said housing,. said valve means being operative 10 in oneposition to establish communication between the evaporator andcompression chamber and between said chamber and the housing, therebyinitiatin first stage compression, and being operative in the otherposition to establish communication between said housing and chamber andbetween said chamber and condenser,

thereby initiating second stage compression,

means in the lower portion of said housing providing an oil sump and areservoir adapted to receive oil from said sump during first stagecompression," means in communication with said chamber for bleeding apart of the refrigerant out of said chamber during second stageoperation and into the reservoir so as to displace oil out of thereservoir during second stage compression, and a conduit extending fromsaid reservoir to the upper part of the housing for discharging thedisplaced oil into the housing to cool the motor-compressor, saidconduit having a section passing exteriorly of the housing to cool suchoil prior to its discharge into said housing.

ELM'ER W. ZEARFOSS, JR.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNTI'ED STATES PATENTS

